How well to you know your Protective Garments
Duty of Care – Provision of Disposable Garments
Employers have a Duty of Care to their employees when providing disposable garments and must take all reasonable and practicable steps to ensure the health and safety of staff in the workplace. This means that it is not sufficient to merely be in compliance with the basic health and safety legislation that is in place which might be unsuitable, inadequate or simply out of date. Employers are obligated to keep abreastwith contemporary knowledge and technology and be fully conversant with potential workplace risks. Note that failure to comply with health and safety legislation can be a criminal offence and in particular, individual directors and company officers may have a personal responsibility and liability under certain national laws such as the UK Health and Safety at Work etc. Act 1974.
To be able to provide an adequate Duty of Care the employer needs to be fully aware of the technical standard that their chosen disposable garment is stated to achieve and that the garment is of the correct standard for the environment and hazards that it is required to protect from. The employer also needs to be confident that the stated standard is actually achieved by the garment and can be supported by the manufacturers test data.
It is also very important to understand what criteria constitutes the passing of the various tests:
Technical Standards and their Limitations
Standards, particularly international standards, play a vital role in ensuring that certain agreed and minimum standards of quality, interoperability and performance are
adhered to. This is in order to protect both the consumer and the environment, and to facilitate the transfer of trade and technology. However, although common standards play a huge role in the specification of protective apparel and other safety equipment, it is not possible to select protective clothing for a given hazard situation simply by relying on industry-wide standards or certifications.
This is partly due to the fact that there can be very wider anging quality and performance latitudes within a given Standard and these permitted margins can equate to big
differences in product capabilities. For example, there is a huge number of protective suits available commercially and although each may carry the European-wide CE mark, there are very wide ranging performance differences for products meeting the same certification “Type”.
For example for the Type 5, 80% inward leakage average results must be lower than 15% of inward leakage. The same applies to the different garment ‘Classes’ relating to nuclear particulate protection where the very broad performance spans of the three bands render them, at best, a very blunt instrument for evaluating the relative performance of different garments
From this it is easily seen that the allocation of a garment to a specific protection type does not necessarily provide an indication that all suits of this type offer the same protection. It is also important to understand that a CE mark in itself does not signify ‘approval’ of any kind. The former EU legislation in the form of Directive 89/686/EEC and new PPE Regulation (EU)
2016/425 make these limitations abundantly clear and in its own words says that the documents merely defines “the basic requirements to be satisfied by personalprotective equipment”. In other words it represents the ‘bare minimum’ rather than the ideal or preferred protective standard. Such standards therefore correspond to an absolute ‘entry level’ of garment performance and represent only a baseline, or starting point, for satisfactory garment selection.
Chemical Protective Clothing – Category III Disposable Garments
Fabric ‘Classes’ Disposable Garments
In addition to the overall garment performance, the European standard for each garment Type also specifies a number of minimum performance requirements, known as the performance Class for the constituent fabrics and seams. These performance properties include technical attributes such as abrasion resistance, puncture resistance, tensile strength, and chemical permeation and penetration . Each fabric property has usually between 1 and 6 performance Classes where Class 6 relates to the highest performance and Class 1 to the minimum performance requirement. This classification system for the fabric helps specifiers to differentiate between different functional characteristics. These mechanical properties are a very important part of the protection equation because they introduce a ‘durability’ factor into the garment appraisal. Because fabric barrier tests are conducted on brand-new garments under static conditions, they do not indicate whether a barrier property will be maintained over time under real working conditions. Protective garments must perform from the moment they are put on to the moment they are taken off and in an operating environment they can be subject to stresses which might compromise the protective performance e.g. by abrasion or tearing.
Mechanical Performance Testing
Fabric Types & Properties Disposable Garments
DuPont™ TYVEK® – Excellent protection and good wearer comfort
Manufactured by a flash-spinning process, Tyvek® fabric is made of strong, continuous, high density polyethylene fibres. The fibres are thermally bonded into a tight, homogeneous and soft fabric that is intrinsically breathable, does not shed fibres (‘linting’) and has inherent barrier properties i.e. not reliant on a thin applied coating or layer. This unique combination of barrier
protection and inherent breathability makes Tyvek® an ideal fabric for a wide range of protective applications.
MICROPOROUS FILM (MPF) – Limited protection and poor wearer comfort
MPF fabrics are a bi-laminate material comprising a thin microporous film bonded to a spunbound polypropylene base. These fabrics offer limited durability since all barrier protection is lost when the protective film layer is abraded. In addition, their low air-permeability characteristics make then much less breathable than other fabrics with all this implies in terms of poor wearer comfort and heat control.
SPUNBOUND/MELTBLOWN/SPUNBOUND (SMS) – Poor protection but good wearer comfort
The performance of SMS fabrics relies on a meltblown polypropylene layer sandwiched between two open spunbound polypropylene layers. This inner polypropylene layer functions as the main filter for particles. However SMS fabrics tend to suffer from limited durability and relatively weak barrier performance due to their relatively open fibre structure. In addition, their high air permeability characteristics significantly compromise the barrier properties of the fabric making it only really appropriate for very basic protection and as a dirt barrier.
Permeation Testing – Normal Breakthrough v Actual Breakthrough Time
It is very important to understand the difference between Normalised Breakthrough Time and Actual Breakthrough Time – Its key that your chosen garment is determined by the Actual Breakthrough Time – again selectively providing test data may avoid declaring the important Actual Breakthrough Time meaning your operator could potentially be at risk. For a detailed understanding of the differenec please click the link at the bottom of this page.
Other Considerations Disposable Garments
In addition to the range of points discussed above, there are a number of further considerations that should be made before a disposable garment choice is made:
Further Fabric Testing
- Liquid Penetration
- Liquid Repellency
- Inefective Agents – blood and body fluids etc
- Radioactive Particles
Whole Garment Performance
- Seam Construction
- Pressurised Exposure
- Tear Resistance
- Overall Garment Cut & Comfort
Extracts included in this article are published by DuPont™ Personal Protection the leading provider of disposal garments and PPE workwear- For further information please click here for the Dupont 2018 Catalogue and Technical Guide or click here for a Garment Permeation Guide.
Full a full guide to the full range of disposable garments and PPE provided by Dupont, please visit the Dupont SafeSpec portal.